Ultraviolet lamp



Aug. 14, 1945. E. L. KOCH ULTRA-VIOLET LAMP Filed June 8, 1944 INVENTOR. (fan Am A. rKacw new Patented Aug. 14, 1945 TES'iP-ATE assass's g ULTRAVIOLET Edward L. Koch, Willlston Park, N. Y., assignor to George W. Gates & 00., Inc, Long Island, a corporation of New York Application June a, 1944, Serial No. ssaess invention relates to invisible ray l p ICIaim.

such as are used for the activation of fluorescent or luminescent materials, and its object is toprovide a novel and improved device of this type.

Another object of the invention is to provide an invisible light unit of the above type which is simple in construction, inexpensive to man facture and assemble, and is considerably more durable than lamps previously employed for similar p p ses. I

Various other objects and advantages will be of the above-mentioned filtering material, and

apparent as the nature of the invention is more fully disclosed.

Although the novel features which are characteristic of this invention are set forth more in detail in the claim'appended hereto, the nature and scope of the invention may be better understood by referring to the following description, taken in connection with the accompanying drawing forming a part thereof, in which a specific embodiment has' been set forth for purposes of illustration.

In the drawing:

Fig. 1 is a longitudinal sectional view through a light unit embodying the invention;

Fig. 2 is an end view thereof and 18. 3 is a transverse section taken on the l e H of Fig. 1.

the following description certain specific te are-used for convenience in referring to the arlous details of the invention. These terms, however, are to be interpreted as broadly as the state'of the art will permit.

Thednvisible light unit shown in the drawing comprises a tubular fluorescent lamp I having end terminals 2 connected to coils 3 within the lamp, and a surrounding concentric tube or shield v4 of filter material as hereinafter more fully described.

The fluorescent lamp I may be of any suitable type adapted to radiate ultra-violet and near ultra-violet light rays, and is usually a low pressure mercury vapor arc lamp of the so-called hot cathode low voltage time.

In practice the fluorescent lamp i is usually coated on the inside with a suitable phosphor or other material adapted to convert a greater proportion of the invisible radiations of the low pressure mercury are into usable ultra-violet rays.

The filter tube 4 may be composed of any suitable translucent glass or plastic material adapted to filter out visible lisht rays and to pass only rays in the ultra-violet and near ultra-violet ranse.

For certain purposes I prefer to construct only one-half the area of the filter tube 1 shown at 4a the other half shown at 4!) of ordinary transparent glass or plastic material. That is, the portion in encompassing of the tube 4 may be composed of material adapted to filter out visible light rays and to transmit only rays in the ultraviolet and near ultra-violet range, while the portion 4b encompassing the remaining 180 of said tube may be composed of material adapted to pass ordinary visible light rays.

when a dual purpose shield of the above type is employed, the lamp may be rotated as a unit through 180 to transmit either ordinary light or "black light, as desired. In the latter case the invisible rays are usually directed upon some fluorescent material such as on an instrument dial forthe purpose of activating and rendering same visible.

The tubes l and l are secured in the desired spaced relation by means of asbestos washers 5 which are mounted adjacent the ends thereof, and the annular spaces between the tubes outwardly of said washers are sealed with fillings of adhesive cement 0. For this purpose I prefer to use an adhesive cement made in paste form, which is easy to apply. The asbestos washers I act as stops for the cement in applying same.

It is to be understood that the above example is only illustrative and that various changes and another portion composed of a material adapted to transmit visible light rays, annular spacers interposed between said lamp and shield adjacent the respective ends thereof, and adhesive means closing the spaces between said lamp and shield outwardly of said spacers and permanently sealing'said shield to said lamp in a unitary struc- EDWARD L. KOCH. 

